Malicious PDF — malware analysis report

Static analysis result for SHA-256 4937ef7a4d6e236f…

MALICIOUS

PDF

71.9 KB Created: 2021-09-18 19:58:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: d796a2bd3bd3d969670537ee1642f333 SHA-1: 279a106ca88b949f2b31c0efe126a50b47f7f529 SHA-256: 4937ef7a4d6e236f21f053d5dcc9d3ae5064fbdd45d2ed7ed6f623f40da795f7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs pointing to various domains, with a high concentration of links on disposable hosting, suggesting a link farm or phishing operation. The `PDF_SEO_DISPOSABLE_LINK_FARM` heuristic specifically indicates this pattern. No scripts were extracted, and the document body was unreadable, but the overall structure and URL distribution strongly suggest a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://lighthousemacau.com/html_upload/file/wuxuvomijari.pdf In PDF document text
    • http://nanopena.cz/upload/file/33968294474.pdfIn PDF document text
    • http://hzbmsj.net/images/upload/File/ruxoxafazegitigez.pdfIn PDF document text
    • http://hbisan.com/userfiles/file/gixalogupageruzelefag.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/zegonupekugub.pdfIn PDF document text
    • https://anaksemut.com/contents/files/69734448644.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/51831698687.pdfIn PDF document text
    • https://www.la-melodie-des-saveurs.fr/ckfinder/userfiles/files/gasunanizeluka.pdfIn PDF document text
    • http://wish-pharma.com/upload/files/9249699469.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613d888d96d56---pezaxorisixobutoxuxunazi.pdfIn PDF document text
    • http://veronikavilla.hu/userfiles/file/fowafinidunojagezovep.pdfIn PDF document text
    • http://rigassprotes.lv/uploadz/file/nidujawelamugupugamekogi.pdfIn PDF document text
    • https://tonitomov.com/picture/file/migiwunabewopalevim.pdfIn PDF document text
    • http://sicilalluminio.it/userfiles/files/vufesalelil.pdfIn PDF document text
    • http://altadirezione-consulting.it/userfiles/files/bokanavegifoto.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/7d6fcbbbfc00050f335266b47c2ac258/14207245726.pdfIn PDF document text
    • http://rtm-plus.com/ckfinder/userfiles/files/39299879729.pdfIn PDF document text
    • https://seo-methodes.com/userfiles/file/84613812497.pdfIn PDF document text
    • http://massarentearchitettura.com/userfiles/files/debisuxubod.pdfIn PDF document text
    • https://jmcoverseaspvtltd.com/uploads/files/genapazavawefoveba.pdfIn PDF document text
    • http://thumpamonpally.com/userfiles/file/53121868638.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/voxanemofol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+eject+flash+drive+from+android+phonePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b82a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB82A 11156 bytes
SHA-256: a7dec5e3c0ddcfb4ec57518c66fd6ed6b12ec80a12d8b06f215fac6e0e384ed0
font_01_sfnt_off0000d20b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD20B 15572 bytes
SHA-256: 61e5bf31745c69c2e3c9117693344c948785a5b02c879db4f16bef50747652bd
font_02_sfnt_off0000f98f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF98F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1